1. Field of the Invention
This invention relates to intake systems in multi-cylinder type internal combustion engines of a type comprising a plurality of intake passages independently leading to cylinders in an engine body and commonly connected to an air cleaner, throttle valves independently disposed in the intake passages, and fuel injection valves also independently disposed in the intake passages at positions downstream of the throttle valves in an intake direction in correspondence to the cylinders.
2. Description of the Prior Art
Such an intake system is already known, for example, from Japanese Utility Model Publication No. 36677/84 or the like.
In the above prior art intake system, however, a plurality of intake passages are commonly connected to a surge tank which is, in turn, connected to an air cleaner. Hence, such system is not space efficiency. Each of the throttle valves is disposed in a substantially central portion of corresponding one of the intake passages, and the length of the intake passage extending downstream of each throttle valve is relatively short, resulting in a reduced intake inertial effect. Moreover, the intake passages communicate with one another through openings provided in a throttle body at a position downstream of the throttle valves. Hence, the intake inertial effect is reduced by such openings.